Lightweight construction

ABSTRACT

A lightweight construction, especially a greenhouse structure, comprises a plurality of pillars ( 12 ) arranged at the periphery of an area of said lightweight construction, said pillars ( 12 ) extending obliquely and outwardly so that an upper end ( 22 ) of said pillars ( 12 ) lies substantially in a vertical plane passing through a respective area border. According to the invention at least one of said pillars ( 12 ) comprises a supporting element ( 14 ), said supporting element being mounted onto said pillar ( 12 ) so as to define a predetermined inclination angle of said pillar ( 12 ).

INTRODUCTION

[0001] The present invention relates to a lightweight construction, ase.g. a greenhouse structure, especially a modular greenhouse.

[0002] Lightweight constructions as e.g. modular greenhouseconstructions are well known and commonly used where large agriculturesurfaces have to be covered. Such a greenhouse structure generallycomprises a plurality of uprights, which are uniformly distributed overan area of the greenhouse. At the periphery of said greenhouse area,pillars are mounted obliquely to extend outwardly in a predeterminedangle, wherein the pillars are arranged so that their upper end liessubstantially in a vertical plane passing through the area border. Thesepillars are braced outwardly to ground anchors and inwardly to acorresponding pillar of the opposite side of the greenhouse, whereby thebracing wire passes over the different uprights arranged between the twoopposite pillars. By securely tightening the wires used to fasten thedifferent pillars together, statically self-contained cells are formed,which can be lined up in both lateral and longitudinal direction to forma single closed structure. With such a modular system, greenhousestructures can be assembled, which cover surfaces of several hectares. Agreenhouse of this kind is e.g. disclosed in FR-A-2209494.

[0003] The assembly of a greenhouse of this kind starts with themounting of the outer pillars at the corners of the surface to becovered. These corner pillars have to be mounted so as to extendobliquely outwardly at a predetermined angle. After these corner pillarsare placed, the intermediate outer pillars are individually mounted inline, whereby these plies have to be equally oriented, so that straightsides are formed. Then the inner uprights are placed at thepredetermined locations and braced together with metal wires at theirupper ends. Finally, the so formed body structure is covered with aplastic sheet to close the greenhouse.

[0004] The problem arising with this method is that the mounting of theoblique outer pillars, i.e. the lining up, the orientation and thebracing of these pillars, requires very high-qualified mountingpersonnel and is furthermore very time consuming. It follows that theassembly of a greenhouse according to this method is rather expensive.

OBJECT OF THE INVENTION

[0005] The object of the present invention is to provide a greenhousestructure, which is easier to assemble.

GENERAL DESCRIPTION OF THE INVENTION

[0006] In order to overcome the above-mentioned problem, the presentinvention proposes a lightweight construction, especially a greenhousestructure, which comprises a plurality of pillars arranged at theperiphery of an area of said lightweight construction, said pillarsextending obliquely and outwardly so that an upper end of said pillarslies substantially in a vertical plane passing through a respective areaborder. According to the invention at least one of said pillarscomprises a supporting element, said supporting element being mountedonto said pillar so as to define a predetermined inclination angle ofsaid pillar.

[0007] The pillars of the present invention can be easily prefabricatedbefore transporting them to the greenhouse construction site. It isclear that when assembling the greenhouse, these prefabricated pillarsonly have to be aligned and suitably distanced in order to define theouter border of the greenhouse. The pillars having a predefinedinclination, no time consuming inclination adjustment is required. Onlythe orientation in a direction substantially perpendicular to saidsupporting structure has to be individually adjusted for each pillar,which does not cause any difficulties to the one skilled in the art.

[0008] The present invention therefore enables a very simple method ofcorrectly mounting the outer pillars of a lightweight construction. Thissimplified assembly method reduces the time necessary for mounting thesepillars by more than a half. Moreover, the simple steps of the methodcan be executed by ordinarily qualified mounting personnel, which areless expensive than highly qualified specialists.

[0009] It follows that the method according to the present inventionsubstantially reduces the mounting time and the overall constructionexpenses for a known greenhouse construction.

[0010] In a first embodiment, said supporting element comprises ahorizontal bar, said horizontal bar being mounted adjacent a lower endof said pillar in such a way that the angle between said pillar and saidhorizontal bar equals said inclination angle of said pillar. If thepillar is mounted in such a way, that the horizontal bar extendshorizontally, the predetermined inclination of the pillar is given. Thepillar may e.g. be mounted in such a way that the horizontal bar restson the ground.

[0011] In a second embodiment, the said supporting element comprises avertical bar, said vertical bar being mounted onto said pillar so thatthe angle between said pillar and said vertical bar equals an anglecomplementary to said inclination angle of said pillar. The vertical barcan e.g. have a length such that the pillar has the right inclination ifthe lower end of the bar touches the ground. This is the case when thelength of the vertical bar equals the length of the vertical leg of arectangular triangle defined by said pillar, said vertical bar and animaginary horizontal line connecting a lower end of said pillar to saidvertical bar. It has to be noted that the vertical bar may be mounted onthe pillar at any suitable location thereof. However a preferredlocation is adjacent an upper end of the pillar, since this embodimentshows the better statical characteristics.

[0012] It will be apparent for the one skilled in the art that the twoembodiments described above can be easily combined. In this case thesupporting element comprising a vertical bar and a horizontal bar, bothconnected with their respective first end to the pillar and connectedtogether at their respective second ends. The supporting structure thusforms a triangle together with the pillar, which provides a very highstability to the element.

[0013] It has to be noted that a supporting element comprising avertical bar mounted on an upper end of the pillar has a doublefunction. In fact, besides its function as auxiliary supportingstructure for supporting the upper end of the pillars during assembly ofthe construction, the vertical bars advantageously also support the sidewall plastic foil of the finished greenhouse. In this way high windloads on the plastic foil can be absorbed by the vertical bars anddeviated into the foundation. Accordingly, the supporting element alsohas a supporting and protecting function for the cover material of thelightweight construction.

[0014] In a preferred embodiment, the vertical bar comprises ananchoring pole, said anchoring pole having a length greater than thelength of the vertical leg of a rectangular triangle defined by saidpillar, said anchoring pole and an imaginary horizontal line connectinga lower end of said pillar to said vertical leg. It follows that in thiscase the anchoring pole extends beyond the point of intersection of thepole and the horizontal line. This lower end of the anchoring pole canthus be used to fixedly mount the pillar by digging the anchor into theground or by embedding into a concrete base, which can be easily formedby filling a suitable trench with concrete. It has to be noted that inthis embodiment, the supporting structure assure a further function. Infact, if securely fixed into a concrete foundation, the anchoring polecan advantageously deviate any upwardly directed traction forces intothe foundation. Such upwardly directed traction forces can be exertede.g. by the bracing wires connecting the pillar to a correspondingpillar of the opposite side of the greenhouse or by wind.

[0015] The correct mounting of the pillar and the associated anchoringpole can be achieved by controlling the vertical orientation of theanchoring pole. In a preferred to alleviate this adjustment, theanchoring pole may comprise at least one mark at the intersectionbetween said anchoring pole and said imaginary horizontal line, saidmark indicating the digging depth of said anchoring pole. By embeddingthe anchoring pole exactly up to the mark, a vertical arrangement of theanchoring pole and thus a correct inclination of the pillar is easilyachieved.

[0016] In a preferred embodiment, each of said pillars comprisesreceiving means for receiving a horizontal distance element. Thedistance element preferably is a horizontal distance bar for mountingbetween the upper ends of two adjacent pillars. The assembly of thegreenhouse is further simplified by these distance bars since thedistance elements define the correct spacing between two adjacentpillars. If the distance bars are mounted on the upper ends of thepillars, these distance bars further define an upper frame of thegreenhouse structure, which provides an improved rigidity of thegreenhouse.

[0017] The pillars advantageously comprise a pedestal mounted on a lowerend of said pillar. It follows that no separate pedestal for the pillarhas to be provided, thus further reducing the mounting time for theentire structure.

[0018] It has to be noted that, after the mounting of the peripheralpillars in the way described above, each pillar may be braced to acorresponding pillar at the opposite side of the greenhouse by means ofwires. After this step, the uprights necessary for supporting the roofof the greenhouse are mounted on their respective positions between theouter pillars, the uprights lifting the bracing wires so that the wiresare further tightened.

DETAILED DESCRIPTION WITH RESPECT OF THE FIGURES

[0019] The present invention will be more apparent from the followingdescription of a not limiting embodiment with reference to the attacheddrawings, wherein

[0020]FIG. 1: shows a preferred embodiment of a pillar of a greenhouse;

[0021]FIG. 2: illustrates the method for assembling the greenhousestructure; and

[0022]FIG. 3: shows further embodiments of pillars with supportingelement.

[0023]FIG. 1 shows preferred embodiment of a prefabricated pillarelement 10 of a greenhouse according to the invention. The pillarelement 10 comprises a pillar 12 for mounting obliquely at a peripheryof a greenhouse structure so as to extend outwardly in a predeterminedangle, and a supporting element 14 for conferring a predeterminedinclination angle α to the pillar 12.

[0024] In the shown embodiment, the supporting structure 14 comprises ananchoring pole 16 mounted on an upper end of the pillar 12 in such away, that the anchoring pole and the pillar define an angle β whichcorresponds to the complementary angle of α, i.e. β=90°−α. Thesupporting structure further comprises an horizontal bar 18 mountedbetween a lower end of said pillar 12 and the anchoring pole 16 so thatthe pillar 12, the anchoring pole 16 and the horizontal bar 18 define anrectangular triangle. This horizontal bar thus confers an improvedstiffness to the pillar element 10.

[0025] The anchoring pole has a length which is greater than thevertical leg of the triangle defined by the different elements. Itfollows that the lower end 20 of the anchoring pole extends beyond thepoint of intersection of the pole and the horizontal bar. This lower endof the anchoring pole may be used to fixedly mount the pillar by diggingthe anchor into the ground or by embedding into a concrete base. Forthis purpose, the lower end 20 of the anchoring pole may be furtherprovided with an specific texture, i.e. notches or the like, forenhancing the adherence to the ground or concrete.

[0026] At the upper end, the pillar 12 may be provided with receivingmeans for receiving a distance element used to place adjacent poles at asuitable distance. This receiving means can e.g. comprise a horizontalsleeve 22 for receiving a spacer tube.

[0027] The assembly of the greenhouse according to the invention isillustrated in FIG. 2. After excavating a suitable trench 30 surroundingthe area of the greenhouse to be mounted, the different outer pillarelements 10 are consecutively aligned starting from one corner. Thepillar elements are arranged in such a way that the lower ends of theanchoring poles extend into the trench 30. The trench thereby providesfor a first reference line for the lateral alignment of the pillarelements. A more exact alignment can be achieved by using a laser basedaligning equipment, which can also be used for vertical alignment.

[0028] The pillars are subsequently mounted, whereby spacer tubes 32 areplaced between two adjacent pillars. These spacer tubes easily ensure anequal spacing between the different pillars. As soon as a pillar ismounted, the trench may be filled with stones and earth or with concretein order to embed the lower end of the anchoring pole, thereby fixingthe position of the pillar.

[0029] After the peripheral row of pillars has been mounted, each pillaris braced to the corresponding pillar at the opposite side of thegreenhouse. Subsequently the uprights necessary for supporting the roofof the greenhouse are erected at the appropriate positions between thepillars, so that a substantially regular grid is formed. The pillars arethereby mounted so as to lift the bracing cables thus further tensioningthese cables. The greenhouse structure is now finished and can becovered e.g. by a suitable plastic foil.

[0030] Further embodiments of pillars with supporting element are shownin FIG. 3. In these embodiments, the supporting element is configured toprovide a support in at least two points lying on either side of avertical plane containing the inclined pillar. It follows that thethree-dimensional orientation of the pillars shown in FIG. 3 is entirelypredetermined.

[0031] In the embodiment shown in FIG. 3a), the said supporting elementcomprises two oblique bars 34 mounted onto said pillar 12, one of saidoblique bars being mounted on either side of a imaginary vertical planecontaining said pillar. As shown, the oblique bars 34 are mounted in acentral region of the pillar 12 and extend downwardly in such a way thatthe lower ends of said bars and the lower end of said pillar define thecorners of an horizontal triangle.

[0032]FIG. 3b) and c) illustrate embodiments of pillars, in which thesupporting element comprises a supporting base 36 which is mountedadjacent a lower end of said pillar 12 in such a way that the anglebetween said pillar and said supporting base equals said inclinationangle of said pillar. The supporting base 36 may simply comprise a platemounted on the lower end of the pillar. In the shown embodiments, thesupporting base 36 comprises several rods 38 extending outwardly fromsaid lower end of said pillar in such a way that the outer ends of saidrods substantially lie in a plane which is cut by said pillar in anangle equal to said inclination angle. It should be noted, that the rodsmay be inclined with respect to said plane (shown in FIG. 3b)) or mayentirely lie in said plane (shown in FIG. 3c)).

[0033] Independent of the embodiment, the outer ends of the rods may beconnected to an annular collar 40 in order to increase the stiffness ofthe supporting base 36.

LIST OF REFERENCE NUMERALS

[0034]10 pillar element

[0035]12 pillar

[0036]14 supporting structure or element

[0037]16 anchoring pole

[0038]18 horizontal bar

[0039]20 lower end of the anchoring pole

[0040]22 horizontal sleeve

[0041]30 suitable trench

[0042]32 spacer tubes

[0043]34 oblique bar

[0044]36 supporting base

[0045]38 rods

[0046]40 annular collar

1. Lightweight construction, especially a greenhouse structure, saidlightweight construction comprising a plurality of pillars arranged atthe periphery of an area of said lightweight construction, said pillarsextending obliquely and outwardly so that an upper end of said pillarslies substantially in a vertical plane passing through a respective areaborder, characterised in that at least one of said pillars comprises asupporting element, said supporting element being mounted onto saidpillar so as to define a predetermined inclination angle of said pillar.2. Lightweight construction according to claim 1, wherein saidsupporting element comprises a horizontal bar, said horizontal bar beingmounted adjacent a lower end of said pillar in such a way that the anglebetween said pillar and said horizontal bar equals said inclinationangle of said pillar.
 3. Lightweight construction according to claim 1or 2, wherein said supporting element comprises a vertical bar, saidvertical bar being mounted onto said pillar so that the angle betweensaid pillar and said vertical bar equals an angle complementary to saidinclination angle of said pillar.
 4. Lightweight construction accordingto claim 3, wherein said vertical bar comprises an anchoring pole, saidanchoring pole having a length greater than the length of the verticalleg of a rectangular triangle defined by said pillar, said anchoringpole and an imaginary horizontal line connecting a lower end of saidpillar to said vertical leg.
 5. Lightweight construction according toclaim 4, wherein said anchoring pole comprises at least one mark at theintersection between said anchoring pole and said imaginary horizontalline, said mark indicating the digging depth of said anchoring pole. 6.Lightweight construction according to claim 1, wherein said supportingelement comprises two oblique bars mounted onto said pillar, one of saidoblique bars being mounted on either side of a imaginary vertical planecontaining said pillar, said oblique bars extending downwardly in such away that the lower ends of said bars and the lower end of said pillardefine the corners of an horizontal triangle.
 7. Lightweightconstruction according to claim 1, wherein said supporting elementcomprises a supporting base, said supporting base being mounted adjacenta lower end of said pillar in such a way that the angle between saidpillar and said supporting base equals said inclination angle of saidpillar.
 8. Lightweight construction according to claim 7, wherein saidsupporting base comprises several rods extending outwardly from saidlower end of said pillar in such a way that the outer ends of said rodssubstantially lie in a plane which is cut by said pillar in an angleequal to said inclination angle.
 9. Lightweight construction accordingto any one of claims 1 to 8, wherein said pillar comprises receivingmeans for receiving a horizontal distance element.
 10. Lightweightconstruction according to claim 9, wherein said distance element is ahorizontal distance bar for mounting between the upper ends of twoadjacent pillars.
 11. Lightweight construction according to any one ofclaims 1 to 10, wherein said pillar comprises a pedestal mounted on alower end of said pillar.